1,352 research outputs found

    Andamios porosos (apatita/colágeno) de origen marino para aplicaciones biomédicas

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    1 póster presentado en las III Xornadas de Investigación BioIntegraSaúde 2015, Vigo 16 xuño 2015.-- E. López-Senra ... et al.FP7/REGPOT-2012-2013.1 (nº 316265, BIOCAPS); UE-INTERREG 2011-1/164 MARMED; Ministerio de Ciencia e Innovación (Project MAT2010-18281)Peer reviewe

    Ener3DMap-SolarWeb roofs: A geospatial web-based platform to compute photovoltaic potential

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    [EN] The effective exploitation and management of renewable energies requires knowledge not only of the energy intensity at the exploitation site but also of the influence of the geometry of the site and its surroundings. For this reason, the efficient processing and interpretation of combined geospatial and energy data is a key issue. This paper presents the development of a web-based tool for the automatic computation of photovoltaic potential on rooftops and on parcels without buildings. The tool called Ener3DMap-SolarWeb Roofs is based on Leaflet and supports WMS, GeoJSON, GeoCSV and KML formats, among others. With these data formats, base maps, geometric data from the rooftops automatically computed from LiDAR and imagery data with self-developed processing algorithms, cadastral data and a solar radiation model are integrated in the tool. These different types of data, the high level of automation and the different scales for which energy data is calculated (hourly, monthly and annually) are the main contributions of the presented tool compared to other existing solutions. The capacities of the tool are tested through its application to analyze the solar potential of rooftops with different shapes and for different solar panel configurations. The accuracy of the results is ensured through the integration of a validated methodology for the computation of geometry and a validated solar radiation model, PVGIS

    Identification of the water stress level in olive trees during pit hardening using the trunk growth rate indicator.

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    Water scarcity is generating an increasing interest in deficit irrigation scheduling. The trunk diameter fluctuations are daily cycles that have been suggested as tools for irrigation scheduling. The trunk growth rate (TGR) was suggested as the best indicator for olive trees during pit hardening. The aim of this work is to clarify how the TGR could be used to identify water stress levels. The experiment was performed during the 2017 season, in a commercial, super-high-density orchard in Carmona (Seville, Spain). Four different irrigation treatments were performed according to midday stem water potential values and TGR. The data obtained were very variable and both indicators presented a wide range of water status throughout the season. The maximum trunk diameter data clearly showed the pattern of the trees water status but the comparison between treatments and the identification of the water stress level was not possible. The average TGR was linked to the midday stem water potential, but with a minimum amount of data. Irrigation scheduling based on the average TGR was difficult because of the great increases in some daily TGR values. For clarity, the pool of data was grouped by midday stem water potential. These water stress levels were characterized using the weekly frequency of TGR values. The increase of water stress reduced the frequency of values between -0.1 and 0.3mm day-1 from 60% to less than 25%. Moderate water stress levels increased the percentage of values lower than -0.3mm day-1 from 7% to 37%. The most severe water stress conditions increased the TGR values between -0.3 and -0.1mm day-1 from 16% up to 22%.IRNASINSTITUTO DE LA GRASACSI

    Influence of environmental factors in the in vitro dehydration of hydrogel and silicone hydrogel contact lenses

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    Purpose: To analyze in vitro the influence of different environmental conditions on the dehydration pattern of seven currently marketed hydrogel (Hy) and silicone hydrogel (Si-Hy) contact lenses (CL). Methods: Three Hy and four Si-Hy CLs were evaluated. CLs were exposed to four different relative humidity (RH) conditions (5%, 30%, 50%, and 70%) and two air flow (AF) rates (0 and 2.75 m/seg) within an environmental chamber. Dehydration was assessed using the gravimetric method. Data were taken at baseline, 5, 10, 15, 20, 30, 45, 60, 90, and 120 minutes of exposure. Dehydration rate (DR), valid dehydration (VD) and stabilization time were calculated. Results: The interaction between RH, AF and the type of the CL material had a significant effect (p 0.03) on DR up to 60 minutes. The maximum differences in VD values among CL occurred around 15 minutes exposure varying from 25.16% to 42.75%. Stabilization time was quicker under the 5%RH with AF condition than under 70% RH without AF one for most CLs. Conclusions: Lower RH seems to increase CL dehydration being further accelerated with the AF presence. The dehydration pattern is material dependent, thus current marketed CLs behave differently under several controlled environmental conditions. Future in vivo studies should confirm these outcomes.The present study was partially supported by Junta Castilla y Leon (GR217 and VA145A11-2); by Junta de Castilla y Leon and European Social Fund (VA317-11); by Junta de Castilla y Leon and European Regional Development Fund (O22/12/VA/0112) and by Ministerio de Economia y Competitividad through Centro para el Desarrollo Tecnologico Industrial (IDI-2006-0676)

    Efficient unidirectional nanoslit couplers for surface plasmons

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    Plasmonics is based on surface plasmon polariton (SPP) modes which can be laterally confined below the diffraction limit, thereby enabling ultracompact optical components. In order to exploit this potential, the fundamental bottleneck of poor light-SPP coupling must be overcome. In established SPP sources (using prism, grating} or nanodefect coupling) incident light is a source of noise for the SPP, unless the illumination occurs away from the region of interest, increasing the system size and weakening the SPP intensity. Back-side illumination of subwavelength apertures in optically thick metal films eliminates this problem but does not ensure a unique propagation direction for the SPP. We propose a novel back-side slit-illumination method based on drilling a periodic array of indentations at one side of the slit. We demonstrate that the SPP running in the array direction can be suppressed, and the one propagating in the opposite direction enhanced, providing localized unidirectional SPP launching.Comment: 13 pages, 4 figure

    Working memory of emotional stimuli: electrophysiological characterization

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    Memorizing emotional stimuli in a preferential way seems to be one of the adaptive strategies brought on by evolution for supporting survival. However, there is a lack of electrophysiological evidence on this bias in working memory. The present study analyzed the influence of emotion on the updating component of working memory. Behavioral and electrophysiological indices were measured from a 3-back task using negative, neutral, and positive faces. Electrophysiological data evidenced an emotional influence on the working memory sensitive P3 component, which presented larger amplitudes for negative matching faces compared to neutral ones. This effect originated in the superior parietal cortex, previously reported to be involved in N-back tasks. Additionally, P3 results showed a correlation with reaction times, where higher amplitudes were associated with faster responses for negative matching faces. These findings indicate that electrophysiological measures seem to be very suitable indices of the emotional influence on working memory

    Near-infrared polarimetric adaptive optics observations of NGC 1068: A torus created by a hydromagnetic outflow wind

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    et al.We present J′ and K′ imaging linear polarimetric adaptive optics observations of NGC 1068 using MMT-Pol on the 6.5-m MMT. These observations allow us to study the torus from a magnetohydrodynamical (MHD) framework. In a 0.5 arcsec (30 pc) aperture at K′, we find that polarization arising from the passage of radiation from the inner edge of the torus through magnetically aligned dust grains in the clumps is the dominant polarization mechanism, with an intrinsic polarization of 7.0 ± 2.2 per cent. This result yields a torus magnetic field strength in the range of 4–82 mG through paramagnetic alignment, and 139+11−20−20+11 mG through the Chandrasekhar–Fermi method. The measured position angle (P.A.) of polarization at K′ is found to be similar to the P.A. of the obscuring dusty component at few parsec scales using infrared interferometric techniques. We show that the constant component of the magnetic field is responsible for the alignment of the dust grains, and aligned with the torus axis on to the plane of the sky. Adopting this magnetic field configuration and the physical conditions of the clumps in the MHD outflow wind model, we estimate a mass outflow rate ≤0.17 M⊙ yr−1 at 0.4 pc from the central engine for those clumps showing near-infrared dichroism. The models used were able to create the torus in a time-scale of ≥105 yr with a rotational velocity of ≤1228 km s−1 at 0.4 pc. We conclude that the evolution, morphology and kinematics of the torus in NGC 1068 can be explained within a MHD framework.ELR and CP acknowledge support from the University of Texas at San Antonio. CP acknowledges support from NSF-0904421 grant. CP and TJJ acknowledge support from NSF-0704095 grant. AA-H acknowledges financial support from the Spanish Plan Nacional de Astronomía y Astrofisíca under grant AYA2012-31447. RN acknowledges support by FONDECYT grant No. 3140436. CRA is supported by a Marie Curie Intra European Fellowship within the 7th European Community Framework Programme (PIEF-GA-2012-327934).Peer Reviewe

    Chemical abundances of late-type pre-main sequence stars in the σ\sigma-Orionis cluster

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    The young σ\sigma-Orionis cluster is an important location for understanding the formation and evolution of stars, brown dwarfs, and planetary-mass objects. Its metallicity, although being a fundamental parameter, has not been well determined yet. We present the first determination of the metallicity of nine young late-type stars in σ\sigma-Orionis. Using the optical and near-infrared broadband photometry available in the literature we derive the effective temperatures for these nine cluster stars, which lie in the interval 4300--6500 K (1--3 \Msuno). These parameters are employed to compute a grid of synthetic spectra based on the code MOOG and Kurucz model atmospheres. We employ a χ2\chi^2-minimization procedure to derive the stellar surface gravity and atmospheric abundances of Al, Ca, Si, Fe, Ni and Li, using multi-object optical spectroscopy taken with WYFFOS+AF2 at at the William Herschel Telescope (λ/δλ7500\lambda/\delta\lambda\sim7500). The average metallicity of the σ\sigma-Orionis cluster is [Fe/H] =0.02±0.09±0.13 = -0.02\pm0.09\pm0.13 (random and systematic errors). The abundances of the other elements, except lithium, seem to be consistent with solar values. Lithium abundances are in agreement with the "cosmic" 7^7Li abundance, except for two stars which show a logϵ(Li)\log \epsilon(\mathrm{Li}) in the range 3.6--3.7 (although almost consistent within the error bars). There are also other two stars with logϵ(Li)2.75\log \epsilon(\mathrm{Li})\sim 2.75. We derived an average radial velocity of the σ\sigma-Orionis cluster of 28±428\pm4km/s. The σ\sigma-Orionis metallicity is roughly solar.Comment: Accepted for publication in Astronomy and Astrophysic

    Brillouin optical time-domain analysis over a 240 km-long fiber loop with no repeater

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    22nd International Conference on Optical Fiber Sensors (OFS2012), Beijing, China, October 14, 2012In this paper we combine the use of optical pulse coding and seeded second-order Raman amplification to extend the\ud sensing distance of Brillouin optical time-domain analysis (BOTDA) sensors. Using 255-bit Simplex coding, the power\ud levels of the Raman pumps and the Brillouin pump and probe signals were adjusted in order to extend the real physical\ud sensing distance of a BOTDA sensor up to 120 km away from the sensor interrogation unit, employing a 240-km long\ud loop of standard single-mode fiber (SSMF) with no repeater. To the best of our knowledge, this is the first time that\ud distributed measurements are carried out over such a long distance with no active device inserted into the entire sensing\ud loop, constituting a considerable breakthrough in the field
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